Wireless user input device providing host link indication

ABSTRACT

A wireless interface device services communications between a wirelessly enabled host and at least one user input device. The wireless interface device includes a wireless interface unit, a processing unit, an input/output unit, and may include a power management unit. The wireless interface unit wirelessly interfaces with the wirelessly enabled host. The processing unit and the wireless interface unit interact to determine when the wireless interface unit has established a link with the wirelessly enabled host. When the wireless interface unit has established a link with the wirelessly enabled host, the processing unit interacts with the input/output unit to direct the input/output unit to output a link established indication. When the wireless interface unit enters a sniff mode or a park mode, a second link established indication may be provided. When the link is taken down or lost, a link non-established indication may be provided.

BACKGROUND

1. Technical Field

The present invention relates generally to digital computers; and moreparticularly to wireless interface devices coupled to digital computers.

2. Related Art

Digital computers have been known in the art for years. Personal digitalcomputers typically include a case, a video display, and one or moreinput/output devices. The case typically includes a power supply, acooling fan, a motherboard, interface ports, peripheral cards, a diskdrive, and other components. Contained on the motherboard are aprocessor, memory, a processor chip set, and one or more peripheralbuses. The peripheral cards interface input/output devices with themotherboard via the peripheral buses. Other input/output devices maycouple directly to the motherboard via appropriate connectors, e.g.,devices coupled via a parallel port, devices coupled via a serial port,and devices coupled via a USB.

Input devices receive input from a user or another source while outputdevices provide output to a user or another destination. Keyboards,computer mice, microphones, scanners, etc. are typically consideredinput devices because they receive input but provide no output.Monitors, speakers, printers, etc. are considered output devices becausethey provide output to the user but receive no input from the user.Other devices, such as touch sensitive monitors, that both receive inputand produce output are considered to be both input and output devices.

Wireless communication technology has rapidly advanced over the past fewyears. Resultantly, computer input/output devices are now being calledupon to wirelessly communicate with their “host” computers. Wirelesskeyboards and mice now couple via wireless connections to their hostcomputers. These “wireless” input devices provide great benefits in thatthey require no wired connections with their host computers. However,the lack of a wired connection also requires that the wireless inputdevices contain their own power supply, i.e., that they be batterypowered. In order to extend the life of their batteries the wirelessinput devices often support power saving modes of operation.Unfortunately, none of these power savings modes reduces powerconsumption to levels that would extend battery life more than a fewweeks. Resultantly, the benefits achieved via wireless connectivity ismet or exceeded by the repeated chore and expense of frequently changingbatteries in the device.

Another shortcoming of these devices relates to their perceived andactual reliability. Because these wireless input devices do notphysically couple to the supported computing device, a user cannotdetermine when the device is “coupled” to the supported computingdevice. Non-responsiveness of the wireless input device may be caused bya failed device, low batteries, non-operational wireless link, oranother operational difficulty. Because users cannot determine whatcauses the wireless input device to be non-responsive, they becomefrustrated and migrate toward wired peripheral devices.

Thus, there is a need in the art for a wireless input device thatprovides feedback to the user to indicate its operational state.

SUMMARY OF THE INVENTION

Thus in order to overcome the shortcomings of the prior devices amongother shortcomings within the wireless user interface realm, a wirelessinterface device constructed according to the present invention servicescommunications between a wirelessly enabled host and at least one userinput device. The wireless interface device includes a wirelessinterface unit, a processing unit, an input/output unit, and may includea power management unit. According to the present invention, theprocessing unit and the wireless interface unit interact to determinewhen the wireless interface unit has established a link with thewirelessly enabled host. Further, when the wireless interface unit hasestablished a link with the wirelessly enabled host, the processing unitinteracts with the input/output unit to direct the input/output unit tooutput a link established indication.

In performing these operations, the wireless interface device indicatesto the user when the wireless user input device is in communication withthe wirelessly enabled host. If the serviced mouse, keyboard, etc. isnot responsive even when link establishment is indicated, the user willthen know that the operational problem is likely with the wirelesslyenabled host. Further, when wireless interface device does not indicatethat a link is established, the user will know that the wireless userinput device requires attention. Attention may require the changing ofbatteries, more proximal location of the wireless user input device tothe wirelessly enabled host, or other action.

The wireless interface device may also include a power management unitthat manages power consumption of the wireless interface device. In suchcase, the wireless interface device supports a plurality of powerconsumption modes including a busy mode and at least one power savingmode. When the wireless interface device is in the busy mode theprocessing unit interacts with the input/output unit to provide a firstlink established indication when the link is established. Further, whenthe wireless interface device is in the at least one power saving modethe wireless interface unit enters a parked mode of operation. When thewireless interface is in the parked mode of operation, the processingunit interacts with the input/output unit to provide a second linkestablished indication. The second link established indication differsfrom the first link established indication to indicate to the user thatthe wireless input device may not be immediately responsive inforwarding input, e.g., key strokes or mouse movement, to the wirelesslyenabled host. Alternatively, when the wireless interface device is inthe at least one power saving mode the wireless interface unit may entera sniff mode of operation. In such case, the processing unit may alsointeract with the input/output unit to provide a second link establishedindication for the same reasons.

In still another operation, when the wireless interface device is in theat least one power saving mode the wireless interface unit enters apower down mode of operation and the processing unit interacts with theinput/output unit to provide a link non-established indication.Moreover, when the wireless interface device transitions from a powersaving mode to the busy mode, the processing unit interacts with theinput/output unit to provide a link being attempted indication. Thesevarious indications provide feedback to the user to indicate the linkstatus of the wireless user input device.

The wireless interface unit may support a wireless interface standard,e.g., one or more versions of the Bluetooth interface standard. Further,the wireless interface device may be constructed on a single monolithicintegrated circuit. The single monolithic integrated circuit may becontained within a wireless mouse or within a wireless keyboard wheninstalled. The wireless mouse and the wireless keyboard are batterypowered such that a single battery or pair of batteries provides alloperating voltage for the device. In another embodiment, the mouse iswired to the keyboard and the wireless interface device is contained inthe keyboard.

Moreover, other aspects of the present invention will become apparentwith further reference to the drawings and specification, which follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a system diagram illustrating a PC host and a wireless mousethat includes a wireless interface device constructed according to thepresent invention;

FIG. 1B is a system diagram illustrating a PC host and a wirelesskeyboard that includes a wireless interface device constructed accordingto the present invention;

FIG. 2 is a schematic block diagram illustrating the structure of awireless mouse that includes a wireless interface device constructedaccording to the present invention;

FIG. 3 is a schematic block diagram illustrating the structure of awireless keyboard that includes a wireless interface device constructedaccording to the present invention;

FIG. 4 is a block diagram illustrating a wireless interface device(integrated circuit) constructed according to the present invention;

FIG. 5 is a block diagram illustrating a wireless interface unit of thewireless interface device of FIG. 4;

FIG. 6 is a block diagram illustrating a processing unit of the wirelessinterface device of FIG. 4;

FIG. 7 is a block diagram illustrating an input/output unit of thewireless interface device of FIG. 4;

FIG. 8 is a block diagram generally showing the structure of anintegrated circuit constructed according to the present invention withparticular detail in the coupling of battery power to the units of thedevice;

FIG. 9 is a logic diagram illustrating operation according to thepresent invention;

FIG. 10 is a logic diagram illustrating operation according to thepresent invention in controlling the power consumption of a serviceddevice;

FIG. 11 is a block diagram generally showing an alternate structure ofan integrated circuit constructed according to the present inventionwith particular detail in the coupling of battery power to the units ofthe device; and

FIG. 12 is a logic diagram illustrating operation according to thepresent invention in providing link establishment indications.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1A is a system diagram illustrating a PC host 102 and a wirelessmouse 104 that includes a wireless interface device constructedaccording to the present invention. As shown in FIG. 1A, the PC host 102wirelessly couples to the wireless mouse 104. In the structure of FIG.1A, the wireless mouse 104 includes a wireless interface device thatoperates to place the wireless mouse in any of a number of reduced poweroperating modes, including a power down mode in which battery life issubstantially extended. As illustrated, the wireless mouse 104 may alsoinclude a link established/non-established indicator 110, which may be alight emitting diode, a liquid crystal display, or another type ofvisual indicator. In other embodiments, the linkestablished/non-established indicator may provide non-visualindications, e.g., audio indication. The operation of the devices of thepresent invention with respect to the indication of link/non-link withthe wirelessly enabled host, PC host 102, will be described further withreference to FIGS. 2, 3, 4, 9 and 12.

FIG. 1B is a system diagram illustrating a PC host 106 and a wirelesskeyboard 108 that includes a wireless interface device constructedaccording to the present invention. The wireless keyboard 108 is batterypowered and operates for extended periods on a single set of batteriesbecause of the greatly reduced power consumption operations according tothe present invention. As illustrated, the wireless keyboard 108 mayalso include a link established/non-established indicator 112, which maybe a light emitting diode, a liquid crystal display, or another type ofvisual or non-visual indicator.

FIG. 2 is a schematic block diagram illustrating the structure of awireless mouse that includes a wireless interface device constructedaccording to the present invention. An integrated circuit 202constructed according to the present invention serves as the wirelessinterface device and couples to various mouse inputs 210. These mouseinputs 210 include x-axis and y-axis inputs as well as a scroll input.The x-axis and y-axis inputs are often referred to a “quadrature”inputs. The components that produce the quadrature inputs are generallyreferred to at numeral 212 and may be constructed from optical inputsinstead of from conventional mechanical inputs. Referenced via numeral214 are the button inputs that are typical with a computer mouse andinclude the left button input, the middle/scroll button input, and theright button input. As is shown, each of the signals produced by themouse are received by integrated circuit 202. The integrated circuit 202may also provide a link established indication/non-indication 216.

Integrated circuit 202 also couples to battery 204, crystal 206 thatproduces a 12 MHz reference frequency, EEPROM 208, and antenna 216. Inone embodiment of the present invention, battery 204 comprises a pair ofeither AA batteries or AAA batteries. Antenna 216 is an internal antennain the described because of the size constraints of the mouse andbecause of the relatively short distance between the PC host and thewireless mouse.

FIG. 3 is a schematic block diagram illustrating the structure of awireless keyboard that includes a wireless interface device (integratedcircuit 202) constructed according to the present invention. As shown inFIG. 3, integrated circuit 202 services a key scan matrix 202 thatprovides inputs from the keyboard. Indicators 304 include num-lock,caps-lock, scroll-lock indicator lights, and linkestablished/non-established indicators that are lit on the keyboard. Theintegrated circuit 202 couples to a battery 204, a crystal 206, anEEPROM 208, and an antenna 216.

In another embodiment (not shown in either FIG. 2 or FIG. 3), theintegrated circuit 202 services both mouse and keyboard input and mayreside internal to either the mouse or the keyboard. As is relativelyapparent to the reader, because the input signals differ, multiplexingor signal sharing may be required. However, different signal lines maybe dedicated for keyboard and for mouse inputs such that no signalsharing is required. As is apparent, when the integrated circuit 202alone services both mouse and keyboard input wired connectivity betweenthe keyboard and the mouse is required.

FIG. 4 is a block diagram illustrating a wireless interface device(integrated circuit) constructed according to the present invention. Asshown in FIG. 4, the wireless interface device 400 includes a processingunit 402, a wireless interface unit 404, an input/output unit 406, and apower management unit 408. The wireless interface unit 404 couples thewireless interface device 400 to antenna 216. The wireless interfaceunit 404 operates according to the Bluetooth specification and inparticular to the Human Interface Device (HID) portion of the Bluetoothspecification.

Processing unit 402, wireless interface unit 404, and input/output unit406 couple with one another via a system on chip (SOC) bus 410.Processing unit 402 includes a processing interface that may be used tocouple the processing unit to one or more devices devices. Input/outputunit 406 includes an input/output set of signal lines that couple thewireless interface device 400 to at least one user input device, e.g.,keyboard and/or mouse.

According to the present invention, the processing unit 402 and thewireless interface unit 404 interact to determine when the wirelessinterface unit 404 has established a link with the wirelessly enabledhost. Further, when the wireless interface unit 404 has established alink with the wirelessly enabled host, the processing unit 402 interactswith the input/output unit 406 to direct the input/output unit 406 tooutput a link established indication.

In performing these operations, the wireless interface device 400indicates to the user when the wireless user input device is incommunication with the wirelessly enabled host. If the serviced mouse,keyboard, etc. is not responsive even when link establishment isindicated, the user will then know that the operational problem islikely with the wirelessly enabled host. Further, when wirelessinterface device does not indicate that a link is established, the userwill know that the wireless user input device requires attention.Attention may require the changing of batteries, more proximal locationof the wireless user input device to the wirelessly enabled host, orother action.

FIG. 5 is a block diagram illustrating a wireless interface unit of thewireless interface device of FIG. 4. The wireless interface unit 404includes a transmit/receive switch 502, a 2.4 GHz transceiver 504, aBluetooth core 506, and a frequency synthesizer 508. Each of thesecomponents is generally known in the field and will be described inminimal detail herein.

The transmit/receive switch 502 couples to antenna 216 and switchesbetween transmit and receive operations. The 2.4 GHz transceiver 504performs all RF front-end operations and operates within a frequencyband and on particular channels as are specified by the Bluetoothoperating standard. The 2.4 GHz transceiver 504 couples to baseband core506, which in the present invention is a Bluetooth baseband core. Suchcoupling is performed via an RF control interface and an RF datainterface. The RF control interface performs the necessary controloperations to guaranty that the 2.4 GHz transceiver 504 and the basebandcore 506 will operate consistently with desired operatingspecifications. The RF data interface transfers both Rx and Tx databetween the 2.4 GHz transceiver 504 and the baseband core 506. Frequencysynthesizer 508 couples to the power management unit 408, to theexternal crystal 206 operating at 12 MHz, and to the 2.4 GHz transceiver504. The frequency synthesizer 508 is controlled to provide an RFfrequency for the 2.4 GHz transceiver 504 which is used to mix with thebaseband signal received from the baseband core during a transmitoperation and to mix with the received RF signal during a receiveoperation. The baseband core 506 couples to other wireless interfacedevices via the SOC bus 410.

FIG. 6 is a block diagram illustrating a processing unit 402 of thewireless interface device of FIG. 4. The processing unit 402 includes amicroprocessor core 602, read only memory 606, random access memory 604,serial control interface 608, bus adapter unit 610, and multiplexer 612.The microprocessor core 602, ROM 606, RAM 604, serial control interface608, bus adapter unit 610, and multiplexer 612 couple via a processor ona chip bus. Multiplexer 612 multiplexes an external memory interfacebetween the processor on a chip bus and a test bus. The bus adapter unit610 interfaces the processor on a chip bus with the SOC. Themicroprocessor core 602 includes a universal asynchronous receivertransmitter interface that allows direct access to the microprocessorcore. Further, the serial control interface 608 provides a serialinterface path to the processor on a chip bus.

FIG. 7 is a block diagram illustrating an input/output unit 406 of thewireless interface device of FIG. 4. The input/output unit 406 includesa keyboard-scanning block 702, a mouse quadrature decoder block 704, anda GPIO control block 706. Each of the keyboard scanning block 702, themouse quadrature decoder block 704, and the GPIO control block 706couple to the SOC bus. Further, each of the keyboard scanning block 702,the mouse quadrature decoder block 704, and the GPIO control block 706couple to I/O via multiplexer 708. This I/O couples to the at least oneuser input device.

In another embodiment of the input/output unit 406, each of the keyboardscanning block 702, the mouse quadrature decoder block 704, and the GPIOcontrol block 706 couples directly to external pins that couple to theat least one user input device.

FIG. 8 is a block diagram generally showing the structure of anintegrated circuit constructed according to the present invention withparticular detail in the coupling of battery power to the units of thedevice. Integrated circuit 800 of FIG. 8 includes a wireless interfaceunit 804, processing unit 802, input/output unit 806, and powermanagement unit 808. The processing unit 802, wireless interface unit804, and input/output unit 806 couple via a SOC bus 410. Further, as waspreviously described, input/output unit 806 couples to at least one userinput device via I/O connection.

With the integrated circuit 800 of FIG. 8, a pad ring 814 surrounds asubstantial portion of the components of the integrated circuit. The padring 814 couples directly to battery 204, which powers the pad ring.Further, input/output unit 806 and power management unit 808 coupledirectly to pad ring 814 to receive their power and voltage. However,processing unit 802 couples to pad ring 814 via processing unit voltageregulation circuitry 812. Further, the wireless interface unit 804couples to pad ring 814 via wireless interface unit voltage regulationcircuitry 810. The processing unit voltage regulation circuitry 812 iscontrolled by the power management unit 808 via control signal PU_EN.Further, the wireless interface unit voltage regulation circuitry 810 iscontrolled by the processing unit 802 using control signal WIU_EN.

The integrated circuit operates in four different power-conservingmodes: (1) busy mode; (2) idle mode; (3) suspend mode; and (4) powerdown mode. Busy mode, idle mode, and suspend mode are described in theBluetooth specification. However, power down mode is unique to thepresent invention. Three different power down modes are describedherein.

In busy mode mode, the Master (host computer) is actively polling theHID (wireless mouse, wireless keyboard, etc.) for data at a polling ratenear 100 polls/second, or about once every 16 Bluetooth slot times (oneBluetooth slot is 625 μS). Continued user activity (keypad strokes,mouse motion, button presses, etc.) keeps the HID in busy mode. If therehas been no activity for a few seconds (determined by particularsettings), operation transitions to idle mode.

In idle mode, the HID requests the master (serviced host) to enter sniffmode with a sniff interval that is chosen based on desired latency andaverage power consumption. In one operation, the sniff interval is 50ms, or about every 80 slot times. Although the HID can wake upimmediately after an event, it may have to wait up to 100 mS to transmitits data to the host, and therefore must have enough buffer space tostore 100 mS of events. If an event occurs, the HID requests the masterto leave sniff mode. If there is no further activity for a longerperiod, the HID transitions from idle mode to suspend mode.

When entering suspend mode, there is a brief return on the connectionstate to busy mode to renegotiate the sniff interval to the suspendinterval time. Then, the HID is parked. In suspend mode, a longer beaconinterval can be used for a lower power state. When in suspend mode, anyuser input detected will result in the HID requesting to be unparked andtransitioned back to the busy mode. When the HID is parked, it consumesless power than when the host is in sniff mode since the HID does nothave to transmit. In suspend mode, the HID just listens to the beaconsto remain synchronized to the master's frequency hopping clock. As longas the master continues transmitting (meaning the host is not turnedoff) the HID will remain in suspend mode mode. If link loss occurs dueto the host being turned off without warning, or the host moving out ofrange, the Lost Link state will be entered. In another embodiment of thepresent invention, while in the suspend mode, the HID continues toremain in the sniff Bluetooth mode rather than being parked, e.g., witha longer sniff interval.

According to the present invention, the power down mode is alsosupported. In the power down mode, the power management unit 808operates the processing unit voltage regulation circuitry 812 and thewireless interface unit voltage regulation circuitry 810 to power downthe processing unit 802 and wireless interface unit 804, respectively.These states of operation will be described further with reference toFIGS. 9, 10, and 11.

FIG. 9 is a logic diagram illustrating operation according to thepresent invention. As illustrated in FIG. 9, a wireless interface deviceoperating according to the present invention operates in four separatepower-conserving modes. These power conservation modes include the busymode, the idle mode, the suspend mode and, the power down mode. Thestate diagram of FIG. 9 shows how each of these modes is reached duringnormal operation.

When the wireless interface device is initially powered up, it entersthe busy mode of operation. In the busy mode of operation, all featuresand wireless operations of the wireless interface device are enabled. Aslong as I/O activity continues, the wireless interface device remains inthe busy mode. However, after expiration of a first timer with no I/Oactivity, the operation moves from the busy mode to the idle mode.Operation will remain in idle mode until the expiration of a secondtimer or until I/O activity occurs.

If while in the idle mode I/O activity occurs, operation returns to thebusy mode. If in the idle mode, if timer 2 expires with no additionalI/O activity, suspend mode is entered. While in suspend mode, if I/Oactivity occurs, operation returns to busy mode. However, if in suspendmode, no additional I/O activity occurs until the expiration of a thirdtimer, power down mode is entered. While in the power down mode,operation will remain in the power down mode until I/O activity occurs.When I/O activity occurs, operation of the wireless interface devicewill move from the power down mode to the busy mode.

When the wireless interface device is in the busy mode the wirelessinterface unit is typically linked to the wirelessly enabled host andthe processing unit interacts with the input/output unit to provide alink established indication. However, when link is lost, the wirelesslyenabled host and the processing unit interact with the input/output unitto provide a link non-established indication. Further, when the wirelessinterface device is in the idle mode the wireless interface unit entersa sniff mode of operation. When the wireless interface is in the sniffmode of operation, the processing unit interacts with the input/outputunit to provide a second link established indication. The second linkestablished indication differs from the first link establishedindication to indicate to the user that the wireless input device maynot be immediately responsive in forwarding input, e.g., key strokes ormouse movement, to the wirelessly enabled host. Alternatively, when thewireless interface device is in the suspend mode the wireless interfacedevices places the wireless interface unit in a parked mode ofoperation. In such case, the processing unit may also interact with theinput/output unit to provide a third (or second) link establishedindication for the same reasons.

In still another operation, when the wireless interface device enters apower down mode of operation the processing unit interacts with theinput/output unit to provide a link non-established indication. In suchcase, the wireless interface unit is powered down. Moreover, when thewireless interface device transitions from a power saving mode to thebusy mode, the processing unit may interact with the input/output unitto provide a link being attempted indication. These various indicationsprovide feedback to the user to indicate the link status of the wirelessuser input device.

In one particular embodiment of these operations, a link establishedindication is indicated by a turned-on non-flashing LED (or otherturn-on indication), a link non-established indication is representedwith a turned-off LED, and the PARK mode and sniff mode are indicated byflashing LEDs. Further, the link being attempted indication may also berepresented as a flashing indicator with a differing flashing period.

FIG. 10 is a logic diagram illustrating operation according to thepresent invention in controlling the power consumption of a serviceddevice. As shown in FIG. 10, once operation in a particular powerconservation state, e.g., busy mode, idle mode, suspend mode, and powerdown mode has commenced, operation will remain in that state untilexpiration of respective timer or I/O activity occurs (step 900).

When power conservation operation occurs to move from the busy mode tothe idle mode (step 902), all portions of the wireless interface deviceremain powered (step 904). However, in the idle mode, the wirelessinterface unit enters a sniff mode in which some of its operations arereduced. Such operations were previously described with reference toFIG. 9. Further, additional information regarding this mode is availablein the Bluetooth HID standard.

When the operation of the wireless interface device transitions from theidle mode to the suspend mode (step 908) all portions of the wirelessinterface device remain powered (step 910). However, the wirelessinterface unit of the wireless interface device enters the park mode,which consumes even less power than does the wireless interface unitwhen in the sniff mode.

When in the suspend mode if an additional timer or inactivity periodexpires, the wireless interface device will transition to the power downmode (step 914). In the power down mode, the wireless interface unit 804is powered down and the processing unit 802 is placed into a powerconservation state (step 916). In a first power down mode, the powermanagement unit 808 powers down the wireless interface unit 804 and theprocessing unit 802. In this mode of operation, battery consumption ofthe wireless interface device is significantly reduced. However, in thepower down operation, the input/output unit 806 remains powered suchthat it can receive input from a coupled user input device. Theinput/output unit 806 indicates to the power management unit 808 when itreceives any user input. When user input is received, the input/outputunit 806 notifies the power management unit 808 that activity hascommenced. In response, the power management unit 808 powers up thewireless interface unit 804 and the processing unit 802 so that theinput can be relayed to the wirelessly enabled host. Second and thirdpower down modes will be described with reference to FIG. 11.

From any of the reduced power operating states, when I/O activity issensed by the I/O block, the wireless input device will transition backto the busy mode (step 920). When such operation occurs, all componentswill be fully enabled (step 922). Then, in the busy mode, the wirelessinterface unit will operate in its normal state in which the masterwireless device, i.e., wirelessly enabled host will poll the wirelessinterface device at 100 times per second. From each of steps 906, 912,918, and 924, operation returns to step 902 wherein the current powerconservation state will be kept until another event occurs.

FIG. 11 is a block diagram generally showing an alternate structure ofan integrated circuit constructed according to the present inventionwith particular detail in the coupling of battery power to the units ofthe device. The integrated circuit 1100 of FIG. 11 is similar instructure to the integrated circuit of FIG. 8. However, with theintegrated circuit of FIG. 11, a clock/voltage regulator 1112 couplesthe processing unit 802 to the pad ring and controls not only thevoltage supply VDD_PU to the processing unit 802 but also the clockinput to the processing unit 802. The integrated circuit 1100 of FIG. 11supports the second and third power down modes (as well as the firstpower down mode) of the present invention.

In a second power down mode, the processing unit 802 instructs thewireless interface unit 804 to power down by communicating with it overthe system bus 410. The processing unit 802 then informs the powermanagement unit 808 that it is ready to have its clock gated. The powermanagement unit 808 then gates the system clock supplied to theprocessing unit 802. The total power consumption of the processing unit802 is a function of the sum of both the static and dynamic current thatit consumes. Dynamic current is generally linearly related to the clockfrequency driving the logic. Static current, also called quiescentcurrent, is typically due to leakage, and is a function of the size ofthe circuit. By gating the clock, the power consumption of theprocessing unit 802 is reduced to only the static component of thecurrent. Particularly in CMOS technology, the static current is on theorder of microamps. Hence, the current pulled by the processing unit 802is reduced to a very small level, while maintaining the state of allmemory circuits within the part. The clock oscillator 1112 is leftrunning in this mode, enabling the power management unit to resume fulloperation of the processing unit by simply ungating the clock.

With a third power down mode, the clock oscillator is turned off. Thishas the same effect as gating the clock, as in the second mode, but alsoeliminates the current consumed in the clock oscillator. When theinput/output unit 806 detects user input, the input/output unit 806notifies the power management unit 808 that activity has commenced. Inresponse, the power management unit 808 powers up the clock oscillator1112 and the processing unit as well as the wireless interface unit s sothat the input can be relayed to the wirelessly enabled host. Table 1illustrates examples of power consumption according to the presentinvention.

TABLE 1 Power Down Modes Wireless I/F Clock Proc. Unit Oscillator UnitI/O Unit Power Comment Busy Mode On On On On 40 mA Full operation PowerDown Off On On/Clock On  1 mA Core leakage + Xtal Osc Mode 1 gatedcurrents incurred Power Down Off Off On On 200 uA Core leakage currentMode 2 incurred Power Down Off Off Off On  50 uA All memory lost, mustdo Mode 3 full reboot

FIG. 12 is a logic diagram illustrating operation according to thepresent invention in providing link establishment indications. Operationcommences at the startup of the wireless interface device (IntegratedCircuit) at step 1202. After startup, the wireless interface unit isinitialized (step 1204) along with the other components of the IC. Afterinitialization, the wireless interface unit attempts to establish al inkwith the serviced wirelessly enabled host (step 1206). If initial linkestablishment is not successful, as determined at step 1208, operationreturns to step 1206. However, if link establishment is successful,operation proceeds to step 1210 wherein the processing unit and thewireless interface unit interact to determine that a link with thewirelessly enabled host has been established. The processing unit theninterfaces with the input/output unit to enable the link establishedindicator (step 1212).

From step 1212, operation proceeds to step 1214 wherein the wirelessinterface device and the wireless link established thereby with thewirelessly enabled host services user input (step 1214). From step 1214,the link may be lost, the link may be dropped, or the link may bealtered. At step 1216, when the link is lost (unintentionally),operation proceeds to step 1206 wherein the wireless interface deviceattempts to reestablish the link with the wirelessly enabled host.During this operation, the processing unit may interact with theinput/output unit to provide an indication that link establishment isbeing attempted. When the link is dropped intentionally (step 1218),which may be done when the wireless interface enters the power downmode, reestablishment is not immediately attempted. Thus, when it isdetermined that link reestablishment should be attempted (step 1222)operation proceeds to step 1206. However, if an attempt to reestablishthe link is not desired, e.g., when the wireless interface device iscompletely powering down, operation ends. Also, from step 1214, the linkmay be altered, e.g., entering sniff mode or park mode (step 1220). Insuch case, operation proceeds to step 1212 wherein the processing unitinterfaces with the input/output unit to provide a second linkestablished indication, for example.

The invention disclosed herein is susceptible to various modificationsand alternative forms. Specific embodiments therefore have been shown byway of example in the drawings and detailed description. It should beunderstood, however, that the drawings and detailed description theretoare not intended to limit the invention to the particular formdisclosed, but on the contrary, the invention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the present invention as defined by the claims.

1. A wireless interface device that services communications between awirelessly enabled host and at least one user input device, the wirelessinterface device comprising: a wireless interface unit that wirelesslyinterfaces with the wirelessly enabled host; a processing unit operablycoupled to the wireless interface unit; an input/output unit operablycoupled to the wireless interface unit and to the processing unit,wherein the input/output unit interfaces to the at least one user inputdevice; wherein the processing unit and the wireless interface unitinteract to determine when the wireless interface unit has established alink with the wirelessly enabled host; wherein when the wirelessinterface unit has established the link with the wirelessly enabledhost, the processing unit interacts with the input/output unit to directthe input/output unit to output a link established indication; a powermanagement unit that manages power consumption of the wireless interfacedevice, wherein the wireless interface device supports a plurality ofpower consumption modes including a busy mode and at least one powersaving mode, wherein: when the wireless interface device is in the busymode the processing unit interacts with the input/output unit to providea first link established indication; when the wireless interface deviceis in the at least one power saving mode the wireless interface unitenters a parked mode of operation; and when the wireless interfacedevice is in the parked mode of operation, the processing unit interactswith the input/output unit to provide a second link establishedindication.
 2. The wireless interface device of claim 1, wherein whenthe wireless interface device transitions from a power saving mode tothe busy mode, the processing unit interacts with the input/output unitto provide a link being attempted indication.
 3. The wireless interfacedevice of claim 1, wherein the wireless interface unit supports one ormore versions of the Bluetooth interface standard.
 4. The wirelessinterface device of claim 1, wherein the wireless interface device isformed as a single monolithic integrated circuit.
 5. A wirelessinterface device that services communications between a wirelesslyenabled host and at least one user input device, the wireless interfacedevice comprising: a wireless interface unit that wirelessly interfaceswith the wirelessly enabled host; a processing unit operably coupled tothe wireless interface unit; an input/output unit operably coupled tothe wireless interface unit and to the processing unit, wherein theinput/output unit interfaces to the at least one user input device; apower management unit that manages power consumption of the wirelessinterface device, wherein the wireless interface device supports aplurality of power consumption modes including a busy mode and at leastone power saving mode; wherein the processing unit and the wirelessinterface unit interact to determine that the wireless interface unithas established a link with the wirelessly enabled host; wherein whenthe wireless interface unit has established the link with the wirelesslyenabled host, the processing unit interacts with the input/output unitto direct the input/output unit to output a link established indication;wherein when the wireless interface device is in the busy mode theinput/output unit outputs a first link established indication; whereinwhen the wireless interface device is in the at least one power savingmode the wireless interface unit enters a sniff mode of operation; andwherein when the wireless interface unit is in the sniff mode ofoperation, the processing unit interacts with the input/output unit toprovide a second link established indication.
 6. The wireless interfacedevice of claim 5, wherein the wireless interface unit supports one ormore versions of the Bluetooth interface standard.
 7. The wirelessinterface device of claim 5, wherein the wireless interface device isformed as a single monolithic integrated circuit.
 8. A method forcontrolling the operation of a wireless interface device that servicescommunications between a wirelessly enabled host and at least one userinput device, the wireless interface device including a wirelessinterface unit, a processing unit, and an input/output unit that couplesto the at least one user input device, the method comprising: thewireless interface unit establishing a wireless link with the wirelesslyenabled host; the wireless interface unit interacting with the processorto indicate to the processing unit that the wireless interface unit hasestablished a link with the wirelessly enabled host; the processing unitinteracting with the input/output unit to direct the input/output unitto output a link established indication; and the input/output unitoutputting a link established indication; the wireless interface devicesupporting a plurality of power consumption modes including a busy modeand at least one power saving mode, wherein: in the busy mode theinput/output unit provides a first link established indication in the atleast one power saving mode the wireless interface unit enters a parkedmode of operation; and when the wireless interface unit is in the parkedmode of operation, the input/output unit provides a second linkestablished indication.
 9. The method of claim 8, wherein when thewireless interface device transitions from a power saving mode to thebusy mode, the processing unit interacts with the input/output unit toprovide a link being attempted indication.
 10. The method of claim 8,wherein the wireless interface unit supports one or more versions of theBluetooth interface standard.
 11. The method of claim 8, wherein the atleast one user input device is selected from the group consisting ofcursor control devices and keypads.